Characterizing the variations of the human body shape is fundamentally important in many applications ranging from animation to product design. 3D scanning technology makes it possible to digitize the complete surfaces of a large number of human bodies, providing much richer information about the body shape than traditional anthropometric measurements. This technology opens up opportunities to extract new measurements for quantifying the body shape. In this paper, we present a new method for extracting the main modes of variations of the human shape from a 3D anthropometric database. Previous approaches rely on anatomical landmarks. Using a volumetric representation, we show that human shape analysis can be performed despite the lack of such information. We first introduce a technique for repairing the 3D models from the original scans. Principal components analysis is then applied to the volumetric description of a set of human models to extract dominant components of shape variability for a target population. We demonstrate a good reconstruction of the original models from a reduced number of components. Finally, we provide tools for visualizing the main modes of human shape variation.